Volume 114  ·   Issue 09  ·  2001

Objective To study the mechanism and effect of lipid lowering drugs in arresting the development of arterial restenosis after angioplasty. Methods De-endothelialization injury of rabbit aortae, common iliac and femoral arteries using balloon angioplasty and the expression of growth factors such as platelet derived growth factor-B (PDGF-B), transforming growth factor β-1 (TGFβ-1), and fibroblast growth factos (bFGF) were investigated. Total serum cholesterol (TC) and triglycerides (TG) were analyzed during and after the treatment using either simvastatin combined with gemfibrozil or simvastatin alone for 6 weeks. Results Serum total cholesterol and triglycerides were only slightly to moderately increased after high cholesterol ration intake lasting for 6 weeks in rabbits of two therapeutic groups (simvastatin plus gemfibrozil or only simvastatin). A positive correlation was found between TC and intimal/medial ratio (r = 0.5873, P<0.05). PDGF-B detected by immuno-histochemistry and RT-PCR analysis showed that the release of PDGF-B was inhibited by simvastatin and gemfibrozil after de-endothelialization. RT-PCR analysis showed that TGFβ-1 was increased in the neointima in two treatment groups but no definite change was seen in the mRNA of bFGF in the smooth muscle cell (SMC) of the balloon-injured arteries even under lipid lowering drug treatment. Conclusion In addition to the lipid lowering effect, both simvastatin and gemfibrozil also influence the release of PDGF-Band TGF-1 in the neointima after de-endothelialization. Chin Med J 2001; 114(9):976-982

Objective To investigate the efficiency of the cytosine deaminase adenoviral/5-fluorocytosine system on prostate cancer cell lines. Methods We used cell culture, infectivity and sensitivity tests, to observe bystander effect by animal tests. Results Established prostate cancer cell lines are eventually infectible by adenoviral vector. The ratio of vector/cell at which infection occurs depends on the specific cell line. The peak of expression of the transferred cytosine deaminase gene occurred in cells at different time, but persisted beyond 11 days. These prostate cell lines are sensitized to 5-fluorocytosine by infection with adenoviral vector carrying the cytosine deaminase gene. Only 5% of the LNCap and 10% of the RM-1 cells were infected and produced 100% cell death. In the animal test, there was significant inhibition of tumor growth at a ratio of 400 vector particles/cell with the systematic treatment of 5-fluorocytosine. Conclusions Adenoviral vector carrying a cytosine deaminase transcription unit can sensitize prostate cancer cell lines to 5-fluorocytosine. The system can significantly inhibit the growth of prostatic tumors in mice. Chin Med J 2001; 114(9):972-975

Objective To investigate the impact of chronic use of high dialysate fill volume on peritoneal transport. Methods Eighteen male SD rats were divided into three groups: control group (Con, n = 6), low fill volume group (LV, n = 6) and high fill volume group (HV, n = 6). Rats in the LV and HV groups received daily intraperitoneal injection of 25 ml (LV, n = 6) or 40 ml (HV, n = 6) 4.25% glucose dialysis solution, once per day for one week. Rats in Con group did not receive any infusion. Forty-eight hours after the last injection, peritoneal equilibrium test was performed in all rats. Results Although the intraperitoneal volume was significantly lower in the LV and HV groups compared with the Con group, there were no significant differences in the intraperitoneal volume between the LV group and HV group. Both the peritoneal fluid absorption rate and the direct lymphatic absorption rate were significantly higher in the LV and HV groups compared with the Con group. Although there was no significant difference in the total peritoneal fluid absorption rate between the LV group and HV group, the direct lymphatic absorption rate was significantly higher in the HV group compared with the LV group (0.015 ± 0.001 ml/min vs 0.010 ±0.003 ml/min, P < 0.05). The solute transport rates were significantly higher in the LV and HV groups compared with the Con group, whereas the difference between the LV group and the HV group was not significant. Conclusions Daily intraperitoneal infusion of 4.25%glucose dialysis solution for seven days results in significantly increased peritoneal fluid and solute transport rats. An additional increase in dialysate infusion volume did not further alter the membrane transport properties except for an increase in peritoneal direct lymphatic absorption rate that may be due to the membrane adaptation to the high fill volume. Chin J Nephrol 2001; 17: 151-154.

Objective To establish a new method for analyzing the cell cycle in tumor which is a kind of cell cycle disease. Methods Mixtures of cyclin E and cyclin A antibodies were incubated with fixed MOLT-4 cells, and measured by flow cytometry. Results We developed a cyclin E + A/DNA flow cytometry analysis method, which may distinguish G0, early G1, late G1, S, G2 and M phase cells, rather than three phases in the DNA content histogram. Conclusion Cyclin E + A/DNA multiparameter flow cytometry can simultaneously differentiate in the same sample six cell groups: G0, early G1, late G1, S, G2 and M phase cells. It performed better than any other cell cycle analysis methods that we have used and has a definite cell biology foundation. Chin Med J 2001; 114(9):967-971

Objective To study the growth inhibition of human hepatoma cells transfected with type Ⅱ insulin-like growth factor receptor (IGF-ⅡR) antisense gene. Methods We constructed the recombinant eucaryotic expression plasmids of IGF-Ⅱ R sense and antisense genes, which were transfected into SMMC-7721 human hepatoma cell line using calcium phosphate coprecipitation, and selected in DMEM supplemented with 500 μg/ml G418 (Geneticin) for 2-3 weeks. Then the total number of colonies formed was counted. The effect of IGF-Ⅱ R antisense gene transfection on endogenous IGF-Ⅱ R mRNA levels was examined by Northern blot, and the growth rate and the ability of the transfected cells to form colonies in soft agar medium were also examined. Results The hepatoma cells transfected with IGF-Ⅱ R antisense gene exhibited significant reduction in endogenous IGF-Ⅱ R messenger RNA (mRNA) levels and loss of their ability for anchorage-independent growth in soft agar. The IGF-Ⅱ R antisense gene suppressed the formation of colonies of SMMC-7721 cells resistant to G418 without alteration on cell growth curve. Conclusion The IGF-Ⅱ R antisense gene expression effectively blocks IGF-Ⅱ to IGF-Ⅱ R autocrine and/or paracrine signal transduction pathway and reverses certain aspects of the cell malignant phenotype. Chin J Dig 2001; 21: 263-265.

Objective To generate and characterize anti-idiotypic monoclonal antibody (Ab2) that bears the internal image of nasopharyngeal carcinoma (NPC) associated antigen. Methods Using NPC monoclonal antibody (Ab1) as immunogen, hybridoma cells were obtained by fusion of SP2/0 myeloma cells with immunized murine spleen cells. Positive clones were screened by Sandwich ELISA and a binding inhibition test. To determine whether Ab2 possess the internal image of the original antigen or not, mice were immunized with Ab2. ELISA and the competitive inhibition assay tested anti-anti-idiotypic antibodies (Ab3) in anti-sera. Cell-mediated immunity to tumors induced by Ab2 was investigated by a delayed-type hypersensitivity response and the mouse T-cell proliferation assay. Results Anti-idiotypic monoclonal antibodies against the monoclonal anti-NPC antibodies FC2 and HNL5 were generated that recognize NPC associated antigens. These Ab2, which were designated 2H4 and 5D3, could inhibit the binding of FC2 or HNL5 to NPC cell lines. Anti-sera from the immunized mice, which contained Ab3, could compete with FC2 or HNL5 for binding with NPC cell by a competitive inhibition assay. Mice immunized with 2H4 or 5D3 coupled with keyhole limpet hemocyanin (KLH), showed a positive and specific delayed-type hypersensitivity (DTH) reaction after stimulation by NPC cells. The mouse T cell proliferative assay indicated that there was a significantly higher proliferative response of the splenocytes in the experimental groups than that in control groups. Conclusions Anti-idiotypic antibodies 2H4 and 5D3 are Ab2 beta bearing the internal image of the epitope of NPC associated antigen. Either 2H4 or 5D3 expressing three-dimensional shapes that resemble the structure of natural antigens could induce humoral and cellular immune response. Chin Med J 2001; 114(9):962-966

Objective To investigate the mechanism of all-trans retinoic acid (ATRA) on the regulation of the cell cycle in gastric cancer cells. Methods The protein level was detected by Western blot. Immunoprecipitation was used in protein kinase activity determination. Cell growth and cell cycle phase were examined by MTT assay and flow-cytometric analysis, respectively. Results ATRA could effectively induce G0/G1 arrest and inhibit cell growth in certain human gastric cancer cell lines. ATRA might induce p21WAF1/GIP1 expression in ATRA-sensitive cell lines through p53-dependent and p53-independent pathways. Induction of p21WAF1/GIP1 caused decrease in CDK4 and CDK2 activities independent of CDK4 and CDK2 protein expression levels. In addition, the dephosphorylated form of Rb protein increased because of the down-regulation of CDK4 and CDK2 activities by ATRA. Conclusions Growth inhibition on gastric cancer cells by ATRA occurs through the regulation of relevant proteins leading to the arrest of cell cycle progression. Chin Med J 2001; 114(9):958-961

Objective To study preoperative diagnosis of advanced gastric cancer (AGC) with pancreatic invasion and their value of surgical management. Methods 420 patients with AGC were estimated preoperatively by electronic gastroscopy and/or endoscopic ultrasound (EUS), epigastric B-ultrasound (BUS) and/or spiral CT scan. Setrum tumor-related antigens including CEA, CA19-9 and CA72-4 were detected preoperatively. Sixty-two (14.8%) out of 420 AGC patients with pancreatic invasion were confirmed by intraoperative and postoperative pathological diagnosis. Of these, 37 patients underwent simultaneous pancreatectomy combined with gastric cancer radical operation, 25 underwent non-radical intervention. Results The diagnosing rate of EUS, spiral CT scan and BUS in patients with AGC with pancreatic invasion preoperatively was 84.2%, 57.1% and 25.8%, respectively. The 1-, 3-, and 5-year survival rate of patients with pancreatic invasion was 55.8%, 23.0% and 6.4%, respectively. There was a significant difference between the survival rate of patients who underwent radical operation combined with simultaneous pancreatectomy and non-radical intervention (P < 0.05). Conclusion EUS and spiral CT scan are helpful in the preoperative diagnosis of AGC with pancreatic invasion. The active surgical management of AGC with pancreatic invasion is advisable, which can improve the survival of some patients. Chin J Surg 2001; 39: 341-343.

Objective To study the long-term result (over 1 year) of microvascular decompression in the treatment of hemifacial spasm. Methods Three hundred and twenty-nine patients with hemifacial spasm were treated with microvascular decompression from July 1986 to June 1999. Results In 97 patients followed up for 1-3 years, the cure rate of spasm was 92.7%, the improvement rate 3. 1%, and no improvement rate 2.1%. In 77 patients followed up for 3-5 years, the cure rate of spasm was 92. 2% and 34 patients followed up for over 10 years, the cure rate of spasm were 91.2%. The recurrence rate of spasm was 5.2%. The occurrence rate of postoperative complications was 5.5%. Conclusion To improve the long efficacy of microvascular decompression hemifacial spasm, it is necessary to avoid injury to the carnial nerves and blood vessels and leaving out responsible blood vessels near hemifacial nerve. Chin J Surg 2001; 39: 349-350.

Objective To investigate the regulation effect of protein kinase ERK on the activation of transcription factor STAT3 in response to IL-6 in the Sko-007 human myeloma cell line. Methods Electrophoretic mobility shift assay (EMSA) and immunoprecipitation (IP) were used to show the activation of STAT3 and ERK in Sko-007 cells in the presence and absence of IL-6. Antisense oligonucloetides of ERK (ERK-AS) were transfected into Sko-007 cells to specifically inhibit the expression and activity of ERK. The changes in the activation of STAT3 in the transfected cells were also exhibited by EMSA. Direct binding between STAT3 and ERK was analyzed by co-IP. Results Both STAT3 and ERK were activated in Sko-007 cells stimulated with IL-6. ERK-AS inhibited STAT3 activation by IL-6. Moreover, activated ERK could form a complex with STAT3 in Sko-007 cells. Conclusion ERK can bind STAT3 directly and be required for its maximal activation in Sko-007 cells stimulated by IL-6. Chin Med J 2001; 114(9):954-957

Objective To evaluate the predictive value of serum neopterin for multiple organ dysfunction syndrome (MODS) in extensively burned patients. Methods Twenty-nine burn patients with TBSA of more than 70% were included in this study, and these patients were divided into two groups according to the occurrence of MODS. Blood samples were obtained on l, 3, 7, 14, 21 and 28 postburn days (PBDs). And serum neopterin levels were determined by radioimmunoassay. To evaluate the predictive power of neopterin, sensitivity, specificity, predictive value of a positive/negative test were calculated for the diagnosis of MODS. Results Serum neopterin levels in MODS group were significantly higher than those in non-MODS group on 3, 7, 14 and 21 PBDs (P < 0.05 - 0.01). And a positive correlation was found between neopterin levels and MODS scores in patients who developed MODS on 3, 7 and 21 PBDs (r=0.470-0.811). In a period of up to 28 PBDs, neopterin levels exceeding 35.0 nmol/L were associated with MODS by a clinical sensitivity of 81.1%, a specificity of 89.9%, a positive predictive value of 81.1%, and a negative predictive value of 89.9%. Conclusion These data indicated that the presence of constant high neopterin serum levels appear to be associated with the development of postburn MODS. Serum levels of neopterin might be a useful marker for the early identification of extensive burned patients at risk for MODS. Chin J Burns 2001; 17: 142-145.

Objective To investigate the role of growth hormone-insulin-like growth factor I (IGF-I) axis in normal pregnancy. Methods Totally, 116 normal pregnant women were recruited from January 1997 to June 1998, with 20 normal nonpregnant women as controls. Maternal growth hormone (GH) and IGF-I concentrations were assayed by RIA and enzyme-linked immunosorbent assay, respectively. Results Maternal serum levels of GH increased throughout gestation, reached a peak at 25 weeks of pregnancy and remained fairly high (χ2 = 40.458, P < 0.0001). There was a significant difference between samples at 5-9 week gestational age and the controls (3.45 μg/L vs 1.61 μg/L, P < 0.05). The maternal serum levels of IGF-I increased rapidly throughout gestation from 29-week gestation and reached a peak of 188.86 μg/L at term delivery (χ2 = 50.224, P < 0.0001). Conclusions Maternal GH levels increased progressively throughout gestation, which correlated with fetal growth. Maternal GH may regulate nutrition supply among mother, placenta and the fetus and play an important role in transporting nutritional substrates by the placenta. The maternal IGF-I in the third trimester may promote fetal growth and placental functions. Chin Med J 2001; 114(9):988-990

Objective To compare the advantages and disadvantages of two procedures: Roux-Y with enterostomy and Roux-Y with spur valve in the treatment of biliary atresia. Methods Twenty-four patients with biliary atresia underwent hepatic portoenterostomy with percutaneous jejunal enterostomy (Group A) and 24 patients underwent Roux-Y with antireflux spur valve (Group B). Clinical data were reviewed retrospectively. Results Ten patients remained alive in the Group A. Among them, 9 survived without jaundice, the oldest one being 9-years old. One of the 9 patients had portal hypertension. The remaining one who survived with jaundice and portal hypertension was 8-years old at follow up. Ten patients in the Group B remained alive. Of them, 8 survived without jaundice and 2 with jaundice. Conclusions Two surgical procedures had similar effects in preventing reflux cholangitis, while spur valve has the benefit of quitting cutaneous enterostomy. Chin Med J 2001; 114(9):986-987

Objective To assess the relationship between apolipoprotein E (apoE) polymorphism and the early onset of coronary heart disease (CHD) and the effect of apoE on lipids and lipoproteins in healthy Chinese subjects. Methods Sixty-eight patients with CHD younger than 55 years (CHD1), 136 patients with CHD older than 65 years (CHD2), and 136 healthy subjects were enrolled, and their plasma levels of triglyceride (TG), total cholesterol (TC) and high density lipoprotein cholesterol (HDL-C) were determined. The apoE genotypes were identified by polymerase chain reaction-restriction fragment length polymorphism. Results apoE 3/4 genotype and E4 allele frequency in the CHD1 group were higher than those in the CHD2 group and healthy subjects, while no differences were found between CHD2 and healthy subjects. Meanwhile, the plasma levels of TC and low density lipoprotein cholesterol (LDL-C) were higher in the CHD2 group than in both CHD1 group and healthy subjects. Each apoE isoprotein has variable TC and LDL-C levels that is E2 (E2/2 + E2/3) < E3(E3/3) < E4(E4/4 + E3/4). Conclusion apoE is one of the genetic factors that affect TC and LDL-C levels, and apoE 4 has a very close relation to CHD, suggesting that apoE 4 is an independent genetic factor of the early onset of CHD. Chin Med J 2001; 114(9):983-985

Objective To investigate the mechanisms of Mal gene down-regulated in human esophageal cancer. Methods We amplified the 5' regulatory region of Mal gene in normal placenta tissue and human esophageal cancer cell lines EC9706, EC8712 and EC109 by optimizing the PCR methods, cloned and sequenced the PCR products and compared the sequence. Results Human esophageal cancer cell lines EC9706, EC8712 and EC109 had the 654 th of 5' regulatory region of Mal gene T to C changes, corresponding codon changed from TCC to CCC, and the amino acid which it codes changed from serine to proline; EC9706 also had the 657 th of 5' regulatory region of Mal gene T to C changes, corresponding codon changed from TGC to CGC, the amino acid which it codes changed from cysteine to arginine; EC8712 had the 139 th of 5' regulatory region of Mal gene A to G changes, corresponding codon changed from GGA to GGG, the amino acid which it codes remained glycine. Conclusion Our results suggest that there are many point mutations in 5' region of Mal gene in human esophageal cancer. Chin J Dig 2001; 21: 271-273.